Students will understand and
apply scientific concepts, principles, principles, and theories pertaining to the physical
setting and living environment and recognize the historical development of ideas in
science.

Key Idea 3: Matter is
made up of particles whose properties determines the observable characteristics of matter
and its reactivity.

Understands and uses the more
advanced features of word processing, spreadsheets, and database software.

Concepts:

Matter

Energy

Phases of matter (solid, liquid,
gas)

Define chemistry

Skills:

Compare and contrast three phases of
matter with respect to volume, energy and shape

Quantify the effects of temperature
and pressure on the volume of a gas

Interpret phase change diagrams

Context for the Task:

Matter and Energy

Essential Questions:

What distinguishes pure science from
applied science?

How can one apply the Law of
Conservation of Mass to a chemical reaction?

In terms of the Kinetic Theory, what
are the properties of solids, liquids, and gases?

How does energy play a role in
chemical reactions?

Using Kinetic Theory, what is the
theoretical basis for gas laws formulated by Boyle, Charles, Dalton, and Graham?

Task:

You will study the effects of heating and cooling a pure
substance through a change of phase. Determine the freezing and melting point temperatures
of a pure substance. Construct a graph in Microsoft Excel using the data for time,
freezing and melting point temperature. Please refer to the Heating and Cooling Lab Manual
for more detailed instructions.

Answer the following questions:

Referring to your graph, determine
the freezing point of 1,4-dichlorobenzene. How does this temperature compare with the
melting point temperature of the same substance as indicated on the graph?

Explain the diagonal parts of the
cooling curve in terms of changes in kinetic and potential energy. Do the same for the
horizontal portions of the cooling curves.

What phase of changes are
exothermic? Endothermic?

In Which phase of a substance do its
particles have the greatest average kinetic energy?